1. Field of the Invention.
This invention relates to a spherulizing furnace for manufacturing vitreous beads comprising a chamber, means for heating the chamber and feed means for delivering a particulate feedstock to one end of the chamber and means for collecting vitreous beads from the other end of the chamber. The invention includes a process of manufacturing vitreous beads in which particulate feedstock is delivered to a heated chamber and passed along it so that the feedstock is heated and converted to vitreous beads whereafter the beads are collected. The invention extends to vitreous beads made by such a process.
2. Description of the Related Art.
In classical spherulizing furnaces, particulate feedstock is fed to the base of a vertical cylindrical combustion chamber where it is surrounded by a burner flame and entrained upwardly. The feedstock particles become spherulized by contact with the flame, and the resulting vitreous beads are carried out of the top of the combustion chamber in a stream of hot gas, and thence to cyclones for grading and collection. Such an arrangement requires very high flow rates of the carrier gas, and since this gas must necessarily be heated by the flame in the combustion chamber, it entails considerable wastage of heat energy, thus adding to the cost of producing the beads.